Shielded circuit breaker



Se t. 15, 1953 M. MALLORY SHIELDED CIRCUIT BREAKER"- Filed 001;. 8, 1951 Fla.

- INVENTOR. MAE/ON MALL 02v rron/Eva.

Patented Sept. 15, 1953 .U NI TED IS F Fl CE 2,652,462 smrznmzncmoursr BREAKER gMarion Mallory, Detroit, Mich. Application October 8, 1951,.Seria'l No. 250312 .11 Claims. (chaos-19) "This invention relates to ashielded circuit breaker and more particularly'toashielddcircuit breaker 'for an automotive ignition distributor.

' It is common practice to grease the cam which operates the circuitbreaker to reduce the friction'between the-cam and therubbing block.

ing and burning of the contact'points' which materially reduces the life of the contact points.

Itis an object of this inventionto-produce a shielded circuit breaker which is of simple structure-and easily assembled on, and'disasse'mbled from,-the circuitbreaker. This-latter feature is important when'one desires to 'i-nsert'a-feeler gauge between the contact points "for proper spacing.

The invention also contemplates a shielded circuit breaker for an automotiveignitionsystem wherein the shielded-breaker unit canbe adjusted towardand away fromthe camw-ithout the necessity for removing the shield.

.Fig. l is a top plan view showing my shielded circuit breaker unit and ignition "distributor-cam.

Fig. 2 isa perspective view of theshield and circuit breaker arm. I

Fig. 3 illustrates the assembly of the shield to the circuit breaker support bracket.

Fig; 4 is aperspectiveof the metal 'portion'of the circuit breaker arm.

Fig.5 is-a sectionalview through the circuit breaker arm showing a closurefor the opening for'thecircuit breaker arm in the shield.

Fig. 6 is a section along. the lineG- -S of Fig. 5.

Referring more particularly to the drawings the principal parts are numbered as foilows: rotatable cam l, circuitbreakeresupport platefi. circuit breaker support bracket 3, pin 4 for pivotally connecting one end of support bracket 3 to mounting plate 2, set screw 5 which passes through an elongated opening 6 in the end of bracket 3 and screws into a threaded opening in plate 2 for securing bracket 3 in whatever position it is adjusted about pivot pin 4, upright arm I integral with bracket 3, circuit breaker spring 8 mounted upon arm I by bolt 9, molded plastic circuit breaker arm bearing 10 and rubbing block ll, rivets I2 for securing spring 8 and channel section circuit breaker arm I3 to rubbing block ll, movable contact point M on arm l3, stationary contact point I5 on upright rand 23 bottomor-restupon the bracket '3.

'2 "arm 1 B of brarikett;upright arm ll integral with bracket 3 and parallel to arm 15, cover f plate. I 8.

Arms I 6 r and 1 I Ttare :substantially identicalin 1 form and the vertical wedges l 9 and :20 converge :downwardly :toward :the base of bracket 3. Cover l8 isima'de of'anyasuitable spring material, such .as spring steelgand consists of: atop porttion 2 l an integral depending front wall -:2 2 and zan integral:'rearwall 23wand opposed end tabs 24 whichroverlap' the upright: arms. or walls l 6 and H. The top"wa;ll-.2l overhangs the bracket arms Ihrand Haas: at 25:;and. 26. :i-Erontwall'22 isg-proivi'ded withuan :openingl'hthrough which circuit .breaker arm: [3 :extends. "The front wall 22- and :rear wall$23 converge inwardly and downwardly sin their:normalunstressed condition, "Fig. 3.

:To assemble'theicover-lfi upon its-supporting arms it and I1, thecover l8.:-is.forced downwardly .over the'side edges l9 and 20' of arms 16 and i! .which flexes walls '22-1and-;23 outwardly or away .fromeach other as. illustrated in the dotted lines -.-Fig. 3. The-cover is-slid-downwardlyuntil the zlower'edges 1:30 ofthe front and rear walls 22 The tabs 2i overlap the arms 16 and Handheld sthe cover it against :en'dwise movement. When cover l8 is in itsfinalaposition, Figs. 2-and 6, .the walls :22=and :23ware under tensionbecause of the-convergingedges ls and ZO-of arms l8 and I1. The'Widthot-each of the-armsifi and .lTat the base-3 is slightly: greater thanthe dis- :tance between the' 'lower edges .39 otthe spring cover Iii-when inits'normal unficxed condition. =Thus, ;the spring tension of walls 22 and 23 of cover l8 co-acts with the converging or tapered sideedges l9 and:20 charms lt andl I -to draw and hold cover; lBdownwardly against bracket-3.

The spr-ing-coverd8 can be-readily removed by graspingthe overhanging-portions 25 and 26 and drawing upwardly uponthe cover.

For closing opening 21 there is provided a non-metallic, electrically non-conducting cover 3| of any suitable material suchas fiber, vulcanized rubber or synthetic rubber such as Neoprene. The cover 3| is provided with an opening 32 therethrough which conforms in shape to the cross section of arm l3, see Fig. 5. The top and bottom edges 33 and 34 of the arm [3 converge inwardly toward the contact 14. This taper co-acts with the cover 3| to hold the same against the front wall 22 of shield I8 to thereby maintain the opening 2! closed. Since cover 31 merely bears against the front wall 22 of shield 18, the cover 3| is free to move back and forth.

relative to wall 22 as the circuit breaker arm swings about its pivot post 35 to open and close contacts 4 and I due to the co-action of rubbing block II and rotary cam l. Cover 3| preferably is of a flexible or elastic material so that it can be slipped over the contact end of arm [3 into position upon the tapered edges 33 and 34 of the arm I3.

I claim:

1. A shield for a circuit breaker comprising a base and opposed end walls and a resilient cover therefor comprising a top wall and side walls, said top and side walls of said cover overlapping the top and side edges of said end walls and resiliently gripping said end walls to hold the cover in place, one side wall having an opening extending to the bottom edge thereof and adapted for receiving a circuit breaker arm, said cover being vertically slidable over said end walls.

2. The shield defined in claim 1 wherein the side edges of said end walls converge inwardly toward the base.

3. The shield defined in claim 2 wherein the side walls of said cover converge inwardly in their unstressed condition and are spaced apart at their lower ends a distance less than the width of said end walls at their lower ends.

4. A circuit breaker assembly for an automotive ignition system comprising a bracket having a base portion and two upstanding opposed walls integral therewith, a post mounted on said bracket, a circuit breaker arm pivotally sup ported on said post, a spring carried by said bracket and connected to said arm and tending to turn said arm about said post as an axis, said arm having a rubbing block adapted for contact with a rotary cam for pivoting said circuit breaker arm, a resilient cover comprising a top wall and side walls, said top and side walls overlapping the top and side edges of said opposed walls and resiliently gripping said opposed walls to hold the cover in place, said post, spring and rubbing block being disposed without the area defined by said cover and end walls, one side wall of said cover having an opening therein through which said circuit breaker arm projects,

said opening having suiiicient clearance with the portion of said breaker arm projecting therethrough to permit pivotal movement of said arm by said cam Without contacting the edges of said opening, said opening extending to an edge of said side wall to permit said cover to be slidably arranged on and removed from said end walls, said circuit breaker assembly being adapted for adjustment as a unit toward and away from said cam.

5. The circuit breaker assembly defined in claim 4 wherein the side edges of said opposed walls converge inwardly toward the base.

6. The circuit breaker assembly defined in claim 5 wherein the side walls of said cover '4 converge inwardly in their unstressed condition and are spaced apart at their lower ends a distance less than the width of said end walls at their lower ends.

7. In combination with a pivoted circuit breaker arm, a shield in the form of a box having top, bottom, side and end walls, an opening in one of said walls through which the breaker arm passes, said opening having substantial clearance with the portion of the breaker arm passing therethrough, a cover overlying said opening and slidably engaging said one wall, said cover surrounding and being supported upon said breaker arm and movable relative to the side wall as the breaker arm pivots.

8. The combination defined in claim 7 wherein the end portion of the breaker arm passing through said opening is tapered inwardly of the shield, said cover being slidably supported on said portion of said breaker arm, whereby the taper co-acts with the cover to hold the cover against the face of the side wall in closing relation with the opening for the breaker arm.

9. The combination defined in claim 8 wherein the cover is formed of an elastic material and the opening through said cover corresponds to the cross sectional contour of the arm adjacent said side wall.

10. In combination with a pivoted circuit breaker arm, a shield comprising a. base and opposed end walls and a resilient cover therefor comprising a top wall and side walls, said top and side walls overlapping the top and side edges of said end walls and slidably engaging and resiliently gripping said end walls to hold the cover in place, one side wall having an opening therein through which said circuit breaker arm passes, said opening having substantial clearance with the surrounding portions of said breaker arm, a closure overlying said opening, said closure being carried by said breaker arm and in sliding relation with the outer face of said side wall whereby said closure remains on said circuit breaker arm when the resilient cover is slidably disengaged from said end walls.

11. The combination defined in claim 10 wherein the top and bottom edges of said circuit breaker arm converge toward the outer end of said arm, the said closure surrounding and having a sliding fit on the tapered end of said breaker arm whereby the closure and tapered end of the breaker arm cooperate to hold the closure in sliding contact with the outer face of said wall adjacent said opening.

MARION MALLORY.

Name Date 1,935,465 Allendorf et a1 Nov. 14, 1933 1,997,288 Anderson Apr. 9, 1935 

